Automatic control clutch



April 4, 1939. J. ELLIOTT ET AL 2,152,733

AUTOMATIC CONTROL CLUTCH Filed Aug. 6, 1937 Patented Apr. 4, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to automatic control clutches. In electric drills for driving a hone or grinding tool for producing perfect fits with full bearing surfaces in holes or passages, it is necessary to actuate a switch for starting and stopping a motor and when the current is turned oli` the motor will still revolve by its own momentum. In order to obtain the best results in honing or grinding, the operator should be freel to employ both hands on the work for applying the Work to the honing or grinding tool before said tool is revolved and to hold the work in this position when the tool begins to revolve so that an exact bearing surface is provided but this is impossible in these types of devices.

It is an object of the present invention to provide a device whereby the work may be applied to the honing or grinding tool while the tool is idle and whereby pressure of the work on the tool will cause an automatic clutching action between a driving and a driven element for initiating rotation of the tool so that the operators hands will be free to hold the Work and direct the work during the grinding or honing.

Another Object of the invention is the provision of a simple and eiiicient device for automatically connecting a driven element carrying a honing or grinding tool to va driving element in which the element is moved into frictio-nal engagement with the driving element so that the tool will be revolved while the operator is using both hands for holding the work in proper position on the tool.

A further object of the invention is the provision of a clutch which is automatically operated for starting and stopping the grinding or honing tool when said tool is expanded in the hole, an automatic clutch operatively connecting the driving and driven members by pressure exerted by the operators body on the Work while both of his hands are free to properly position the work, the honing or grinding tool being stopped immediately upon release of pressure.

This invention will be best understood from a consideration of the following detailed description, in view of the accompanying drawing forming a part of the specification; nevertheless, it is to be understood that the invention is not confined to the disclosure, being susceptible of such changes'and modifications as define no-material departure from the salient features of the invention as expressed in the appended claim.

In the drawing:

Figure 1 is a vertical section in elevation of a tool constructed in accordance with the principles of our invention,

Figure 2 is a vertical section taken along the line v2--2 of Figure 1,

Figure 3 is a transverse vertical section taken along the line 3-3 of Figure 1,

Figure 4 is a fragmentary view in perspective showing the connection between a tool and a driven member,

Figure 5 is a vertical section taken along the 10 line 5--5 of Figure 1, and

Figure 6 is a longitudinal side View of a modied form of the device.

Referring more particularly to the drawing, Ill designates a base member upon which is mounted a pedestal II of any suitable configuration and which carries a bearing I2 to support a stationary shaft or axle I3.

'A pulley I5 has a hub portion I6 received by a bushing I'I and the pulley is mounted for rotation 20 on the axle I3. A thrust bearing I8 is located between a shoulder I9 formed on the hub I6 and the inner end 0f the bearing I 2 of pedestal I I. The pulley I5 is driven by a belt connected with any suitable source of power.

A disc 20 is loosely mounted on the axle I3 and is normally maintained out of contact with a flat face 2| of the pulley I5 in a manner which will be presently described.

A clutch facing or disc 22 is secured at 23 to the disc 20 and'has a central opening 25 into which a washer y24 is adapted to projectwhen the disc 22 engages the flat face 2| of the pulley I5.

'I'he disc 20 is provided with an elongated hub section or shaft which is hollow and receives the axle I3. The outer end of the axle is provided with a pocket 3| in which is slidably mounted a sleeve 32 having a flanged end 33. A coil spring 34 is mounted in the sleeve 32 and has one end abutting the closed end 33 while the 40 other end is seated upon the inner end 35 of the pocket 3|. The anged and closed end 33 of the sleeve 32 abuts a shoulder 36 formed by reducing the passage in the sleeve 30 as shown at 31. 'Ihus the spring 34 will tend at all times to move the sleeve-30 and the disc 20 outwardly from the pulley |5 so that the disc 2.2 will be normally out of engagement with the flat face 2| of the pulley I5 when the device is inoperative.

The extreme outer end of the sleeve 30 is provided with a diametrical slot 40 which has a bayonet end, as shown at 4I, to provide seats for the reception of the ends 42 of a pin 43 which is disposed diametrically in a passage within the reduced end 44 of a honing or grinding tool 45. The member 45 may be a chuck for carrying the honing or grinding tool or the tool may be so constructed that it will be provided with the reduced portion 44 and the pin 43.

The operation of the device shown in Figs. 1 to 5 is as follows: The motive power is set in action so that it will revolve the pulley I on the axle I3. However, since the disc 2U and likewise the disc 22 are spaced from the surface 2| of the pulley I5 the clutching element or discs 20 and 22 remain stationary so that the operator may use both hands for properly applying the work to the honing or grinding tool at the outer end of the mem,- ber 45. It is only necessary for the operator then to exert pressure on the work by his body until the disc 22 is moved into engagement with the pulley I5 whereby the disc 20, the sleeve 30 and the member 45 will be revolved.

When pressure is removed from the members 2liA and 3B a coil spring 34 will force the disc 20 and likewise the disc 22 away from the pulley I5 whence the disc 2U will stop and remain idle while the pulley I5 is revolved.

Referring more particularly to Fig. 6 an electrically driven member 50 is provided with a handle 5I and a clamp 52 is secured to the handle 5I. The member 50 drives a shaft 53 and a disc 54 secured bymeans of a hub 5.5 and a pin 56 to the shaft 53.

The shaft 53 extends beyond the disc 54 and supports a hub or sleeve 38a formed integrally with` a clutch disc 25a. which has a friction lining or disc 22a on the face adjacent the disc 54. n

The remaining parts of the shaft 53 and the sleeve 30a are identical with the constructions shown in Figs. 1 and 4 and therefore the description need not be repeated since the same refer'- ence characters are applied to the various parts.

An arm 6D is carried by the clamp or bracket 52, is adjustable longitudinally of the shaft 53,

and is adapted to be held in place by means of a set screw 6I. The arm 60 is slidably mounted withinr a slot 62 in the clamp 52.

A bent portion` 53 extends upwardly and over the disc 54 and 25a. and has a downwardly bent portion 54 upon which is carried a friction disc 65.. In Fig. l the axle i3 [is held stationary in the bearing I2 and the pulley I5 revolves on said axle.

In Fig. 6, however, the pilot shaft 53 is revolved so that when end pressure is released on the sleeve 30a and the disc 25a said disc and sleeve will tend to rotate due to the fact that it is mounted upon the revolving pilot shaft 53. Thus when end pressure is removed from said sleeve and disc, the spring 34 will move the disc 20a from the revolving disc 54 and force the same into engagement with the friction plate 55 on the arm 54 and thus stop the disc 25a from. further rotation.

We claim.:

In a power driven tool, a standard, an axle secured to saidl standard and projecting horizontally therefrom, a pulley mounted for rotation on said axle and having a flat face, a hollow shaft mounted for sliding and rotative movement on the axle and provided with an internal shoulder, a disc rigidly connected to the inner end of the shaft and provided with a clutch face adapted to be moved into engagement with the flat face of the pulley 'when the shaft is reciprocated in one direction, the free end of the axle having a pocket, a sleeve in the pocket and provided with a closed end abutting the shoulder, a spring in the pocket and sleeve urging the hollow shaft and likewise the disc away from the pulley and means on the free end of the shaft for removably connecting a tool thereto.

JOE ELLIO'I'I. EDWARD E. GARNER. 

